It makes us look like a backwoods where the prime minister of our closest neighbour...is unable to come to friendly shores,

George Galloway

First Minister Henry McLeish said he disagreed with Mr Roy's claim that there would have been a security risk, and issued an invitation for Mr Ahern to visit at a future date.

That has been accepted by the Irish prime minister, who had been due to unveil a memorial to victims of the Irish potato famine at Carfin, in Lanarkshire, after watching Sunday's league clash between Celtic and Rangers.

George Galloway, Labour MP for Glasgow Kelvin, was scathing over Mr Roy's warning to the Irish authorities.

He said: "I think it is an underestimation of the people of Lanarkshire and the people of Scotland and I think it makes us look like Mississippi.

"It makes us look like a backwoods where the prime minister of our closest neighbour and closest friend, and a friend of Scotland moreover, is unable to come to friendly shores, a religious place, because there might be trouble."

Irish government sources were reported to have been "incandescent" with the way matter was handled and Mr Ahern was said to be very disappointed that he would not be visiting on Sunday.

Former Scottish National Party leader Alex Salmond echoed Mr Galloway's sentiments.

Frank Roy wrote to the Taoiseach

He said: "This is a most extraordinary bungle, this damaging Scotland's international reputation and is deeply offensive to the prime minister of a friendly country.

"Even if it were true, which it's certainly not, that you couldn't have such an event in Scotland then surely the right thing to do, if we felt Scotland was so badly sectarian, would to have the event, to confront it."

Mr Roy said he had acted alone in his contacts with Mr Ahern's office, but David McLetchie, the leader of the Scottish Tory Party, speculated that former Scottish Secretary and new Northern Ireland Secretary, Dr John Reid, may have been involved.

He said: "It is a matter of considerable regret that John Reid and his sidekick Frank Roy have pressed the panic button and created a situation that many will view as a victory for bigots which does profound damage to the image of Scotland in the world."

Henry McLeish, Scotland's first minister, told the Scottish Parliament Mr Ahern would be formally invited to come to Scotland in an effort to smooth the feathers ruffled by the debacle.

One of the worst nights in my constituency for policing is the night of any Old Firm game

Frank Roy MP

Mr Ahern was also due to attend the crucial league match between Celtic and Rangers before going to Lanarkshire for the unveiling.

But Mr Roy contacted Mr Ahern's office to say the Old Firm clash would see the police at full stretch, potentially undermining his security.

He said: "One of the worst nights in my constituency for policing is the night of any Old Firm game, and quite frankly we don't need this as well.

"There was an Old Firm game last night and there could be some bad blood carried over to Sunday.

Alex Salmond: "An extraordinary bungle"

"I think it was totally unnecessary and totally inappropriate.

"I think Mr Ahern was badly advised and I told him I was very sorry that no-one from the Irish embassy contacted me to ask my advice.

"The Taoiseach would be most welcome in my constituency at any other time."

Mr Roy added: "I wouldn't even have a problem with the unveiling being on the morning of the game, but I do have a problem with it being after the final whistle in the dark."

Mr Ahern's spokesman said that he had accepted an invitation to visit Scotland at a later date, and would keep his promise to unveil the memorial.

I think it is unfortunate that they have picked the date of the unveiling to coincide with the Old Firm match.

Cara Henderson, Nil By Mouth

"We are acting on the advice we received through the consulate in Edinburgh that the ceremony should not go ahead this weekend, and we have agreed with the organisers it would be rescheduled for later on in the year," she said.

"The Taoiseach has said he is disappointed that he is not in a position to attend this weekend, but he fully expects to attend the unveiling of the memorial at some stage."

Mr Roy won support from a leading campaigner against sectarianism.

Cara Henderson, founder of Nil By Mouth (NBM), said: "I think it is unfortunate that they have picked the date of the unveiling to coincide with the Old Firm match.

"This was unwise given the sensitivity of the situation and to some extent I can sympathise with Frank Roy and I feel he has been quite brave to raise his concerns."

She added: "However, by cancelling the Taoiseach's visit we are in a sense giving in to the bigots and preventing Scotland from confronting the matter head on, however embarrassing this could have been.

Ms Henderson founded the NBM in 1999 in memory of her friend, Mark Scott who was murdered at Bridgeton Cross, Glasgow, in 1995 because he was wearing a Celtic shirt.